X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FLinker%2FLinkModules.cpp;h=5979dc6fbc6f3a578829b0a4e44fc775649af041;hb=d1ec48c641f76d4c0e5b7cb357a1333d4fb75c4a;hp=4a0caada51d8581a37b027a89c9a4c76a9b8e732;hpb=4ee451de366474b9c228b4e5fa573795a715216d;p=oota-llvm.git diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp index 4a0caada51d..5979dc6fbc6 100644 --- a/lib/Linker/LinkModules.cpp +++ b/lib/Linker/LinkModules.cpp @@ -26,6 +26,7 @@ #include "llvm/Assembly/Writer.h" #include "llvm/Support/Streams.h" #include "llvm/System/Path.h" +#include "llvm/ADT/DenseMap.h" #include using namespace llvm; @@ -52,7 +53,6 @@ static std::string ToStr(const Type *Ty, const Module *M) { // Inputs: // DestTy - The type to which we wish to resolve. // SrcTy - The original type which we want to resolve. -// Name - The name of the type. // // Outputs: // DestST - The symbol table in which the new type should be placed. @@ -61,121 +61,203 @@ static std::string ToStr(const Type *Ty, const Module *M) { // true - There is an error and the types cannot yet be linked. // false - No errors. // -static bool ResolveTypes(const Type *DestTy, const Type *SrcTy, - TypeSymbolTable *DestST, const std::string &Name) { +static bool ResolveTypes(const Type *DestTy, const Type *SrcTy) { if (DestTy == SrcTy) return false; // If already equal, noop + assert(DestTy && SrcTy && "Can't handle null types"); - // Does the type already exist in the module? - if (DestTy && !isa(DestTy)) { // Yup, the type already exists... - if (const OpaqueType *OT = dyn_cast(SrcTy)) { - const_cast(OT)->refineAbstractTypeTo(DestTy); - } else { - return true; // Cannot link types... neither is opaque and not-equal - } - } else { // Type not in dest module. Add it now. - if (DestTy) // Type _is_ in module, just opaque... - const_cast(cast(DestTy)) - ->refineAbstractTypeTo(SrcTy); - else if (!Name.empty()) - DestST->insert(Name, const_cast(SrcTy)); + if (const OpaqueType *OT = dyn_cast(DestTy)) { + // Type _is_ in module, just opaque... + const_cast(OT)->refineAbstractTypeTo(SrcTy); + } else if (const OpaqueType *OT = dyn_cast(SrcTy)) { + const_cast(OT)->refineAbstractTypeTo(DestTy); + } else { + return true; // Cannot link types... not-equal and neither is opaque. } return false; } -static const FunctionType *getFT(const PATypeHolder &TH) { - return cast(TH.get()); -} -static const StructType *getST(const PATypeHolder &TH) { - return cast(TH.get()); +/// LinkerTypeMap - This implements a map of types that is stable +/// even if types are resolved/refined to other types. This is not a general +/// purpose map, it is specific to the linker's use. +namespace { +class LinkerTypeMap : public AbstractTypeUser { + typedef DenseMap TheMapTy; + TheMapTy TheMap; + + LinkerTypeMap(const LinkerTypeMap&); // DO NOT IMPLEMENT + void operator=(const LinkerTypeMap&); // DO NOT IMPLEMENT +public: + LinkerTypeMap() {} + ~LinkerTypeMap() { + for (DenseMap::iterator I = TheMap.begin(), + E = TheMap.end(); I != E; ++I) + I->first->removeAbstractTypeUser(this); + } + + /// lookup - Return the value for the specified type or null if it doesn't + /// exist. + const Type *lookup(const Type *Ty) const { + TheMapTy::const_iterator I = TheMap.find(Ty); + if (I != TheMap.end()) return I->second; + return 0; + } + + /// erase - Remove the specified type, returning true if it was in the set. + bool erase(const Type *Ty) { + if (!TheMap.erase(Ty)) + return false; + if (Ty->isAbstract()) + Ty->removeAbstractTypeUser(this); + return true; + } + + /// insert - This returns true if the pointer was new to the set, false if it + /// was already in the set. + bool insert(const Type *Src, const Type *Dst) { + if (!TheMap.insert(std::make_pair(Src, PATypeHolder(Dst))).second) + return false; // Already in map. + if (Src->isAbstract()) + Src->addAbstractTypeUser(this); + return true; + } + +protected: + /// refineAbstractType - The callback method invoked when an abstract type is + /// resolved to another type. An object must override this method to update + /// its internal state to reference NewType instead of OldType. + /// + virtual void refineAbstractType(const DerivedType *OldTy, + const Type *NewTy) { + TheMapTy::iterator I = TheMap.find(OldTy); + const Type *DstTy = I->second; + + TheMap.erase(I); + if (OldTy->isAbstract()) + OldTy->removeAbstractTypeUser(this); + + // Don't reinsert into the map if the key is concrete now. + if (NewTy->isAbstract()) + insert(NewTy, DstTy); + } + + /// The other case which AbstractTypeUsers must be aware of is when a type + /// makes the transition from being abstract (where it has clients on it's + /// AbstractTypeUsers list) to concrete (where it does not). This method + /// notifies ATU's when this occurs for a type. + virtual void typeBecameConcrete(const DerivedType *AbsTy) { + TheMap.erase(AbsTy); + AbsTy->removeAbstractTypeUser(this); + } + + // for debugging... + virtual void dump() const { + cerr << "AbstractTypeSet!\n"; + } +}; } + // RecursiveResolveTypes - This is just like ResolveTypes, except that it // recurses down into derived types, merging the used types if the parent types // are compatible. -static bool RecursiveResolveTypesI(const PATypeHolder &DestTy, - const PATypeHolder &SrcTy, - TypeSymbolTable *DestST, - const std::string &Name, - std::vector > &Pointers) { - const Type *SrcTyT = SrcTy.get(); - const Type *DestTyT = DestTy.get(); - if (DestTyT == SrcTyT) return false; // If already equal, noop +static bool RecursiveResolveTypesI(const Type *DstTy, const Type *SrcTy, + LinkerTypeMap &Pointers) { + if (DstTy == SrcTy) return false; // If already equal, noop // If we found our opaque type, resolve it now! - if (isa(DestTyT) || isa(SrcTyT)) - return ResolveTypes(DestTyT, SrcTyT, DestST, Name); + if (isa(DstTy) || isa(SrcTy)) + return ResolveTypes(DstTy, SrcTy); // Two types cannot be resolved together if they are of different primitive // type. For example, we cannot resolve an int to a float. - if (DestTyT->getTypeID() != SrcTyT->getTypeID()) return true; + if (DstTy->getTypeID() != SrcTy->getTypeID()) return true; + // If neither type is abstract, then they really are just different types. + if (!DstTy->isAbstract() && !SrcTy->isAbstract()) + return true; + // Otherwise, resolve the used type used by this derived type... - switch (DestTyT->getTypeID()) { - case Type::IntegerTyID: { - if (cast(DestTyT)->getBitWidth() != - cast(SrcTyT)->getBitWidth()) - return true; - return false; - } + switch (DstTy->getTypeID()) { + default: + return true; case Type::FunctionTyID: { - if (cast(DestTyT)->isVarArg() != - cast(SrcTyT)->isVarArg() || - cast(DestTyT)->getNumContainedTypes() != - cast(SrcTyT)->getNumContainedTypes()) + const FunctionType *DstFT = cast(DstTy); + const FunctionType *SrcFT = cast(SrcTy); + if (DstFT->isVarArg() != SrcFT->isVarArg() || + DstFT->getNumContainedTypes() != SrcFT->getNumContainedTypes()) return true; - for (unsigned i = 0, e = getFT(DestTy)->getNumContainedTypes(); i != e; ++i) - if (RecursiveResolveTypesI(getFT(DestTy)->getContainedType(i), - getFT(SrcTy)->getContainedType(i), DestST, "", - Pointers)) + + // Use TypeHolder's so recursive resolution won't break us. + PATypeHolder ST(SrcFT), DT(DstFT); + for (unsigned i = 0, e = DstFT->getNumContainedTypes(); i != e; ++i) { + const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i); + if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers)) return true; + } return false; } case Type::StructTyID: { - if (getST(DestTy)->getNumContainedTypes() != - getST(SrcTy)->getNumContainedTypes()) return 1; - for (unsigned i = 0, e = getST(DestTy)->getNumContainedTypes(); i != e; ++i) - if (RecursiveResolveTypesI(getST(DestTy)->getContainedType(i), - getST(SrcTy)->getContainedType(i), DestST, "", - Pointers)) + const StructType *DstST = cast(DstTy); + const StructType *SrcST = cast(SrcTy); + if (DstST->getNumContainedTypes() != SrcST->getNumContainedTypes()) + return true; + + PATypeHolder ST(SrcST), DT(DstST); + for (unsigned i = 0, e = DstST->getNumContainedTypes(); i != e; ++i) { + const Type *SE = ST->getContainedType(i), *DE = DT->getContainedType(i); + if (SE != DE && RecursiveResolveTypesI(DE, SE, Pointers)) return true; + } return false; } case Type::ArrayTyID: { - const ArrayType *DAT = cast(DestTy.get()); - const ArrayType *SAT = cast(SrcTy.get()); + const ArrayType *DAT = cast(DstTy); + const ArrayType *SAT = cast(SrcTy); if (DAT->getNumElements() != SAT->getNumElements()) return true; return RecursiveResolveTypesI(DAT->getElementType(), SAT->getElementType(), - DestST, "", Pointers); + Pointers); + } + case Type::VectorTyID: { + const VectorType *DVT = cast(DstTy); + const VectorType *SVT = cast(SrcTy); + if (DVT->getNumElements() != SVT->getNumElements()) return true; + return RecursiveResolveTypesI(DVT->getElementType(), SVT->getElementType(), + Pointers); } case Type::PointerTyID: { + const PointerType *DstPT = cast(DstTy); + const PointerType *SrcPT = cast(SrcTy); + + if (DstPT->getAddressSpace() != SrcPT->getAddressSpace()) + return true; + // If this is a pointer type, check to see if we have already seen it. If // so, we are in a recursive branch. Cut off the search now. We cannot use // an associative container for this search, because the type pointers (keys - // in the container) change whenever types get resolved... - for (unsigned i = 0, e = Pointers.size(); i != e; ++i) - if (Pointers[i].first == DestTy) - return Pointers[i].second != SrcTy; - + // in the container) change whenever types get resolved. + if (SrcPT->isAbstract()) + if (const Type *ExistingDestTy = Pointers.lookup(SrcPT)) + return ExistingDestTy != DstPT; + + if (DstPT->isAbstract()) + if (const Type *ExistingSrcTy = Pointers.lookup(DstPT)) + return ExistingSrcTy != SrcPT; // Otherwise, add the current pointers to the vector to stop recursion on // this pair. - Pointers.push_back(std::make_pair(DestTyT, SrcTyT)); - bool Result = - RecursiveResolveTypesI(cast(DestTy.get())->getElementType(), - cast(SrcTy.get())->getElementType(), - DestST, "", Pointers); - Pointers.pop_back(); - return Result; + if (DstPT->isAbstract()) + Pointers.insert(DstPT, SrcPT); + if (SrcPT->isAbstract()) + Pointers.insert(SrcPT, DstPT); + + return RecursiveResolveTypesI(DstPT->getElementType(), + SrcPT->getElementType(), Pointers); } - default: assert(0 && "Unexpected type!"); return true; } } -static bool RecursiveResolveTypes(const PATypeHolder &DestTy, - const PATypeHolder &SrcTy, - TypeSymbolTable *DestST, - const std::string &Name){ - std::vector > PointerTypes; - return RecursiveResolveTypesI(DestTy, SrcTy, DestST, Name, PointerTypes); +static bool RecursiveResolveTypes(const Type *DestTy, const Type *SrcTy) { + LinkerTypeMap PointerTypes; + return RecursiveResolveTypesI(DestTy, SrcTy, PointerTypes); } @@ -200,10 +282,14 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { const std::string &Name = TI->first; const Type *RHS = TI->second; - // Check to see if this type name is already in the dest module... + // Check to see if this type name is already in the dest module. Type *Entry = DestST->lookup(Name); - if (ResolveTypes(Entry, RHS, DestST, Name)) { + // If the name is just in the source module, bring it over to the dest. + if (Entry == 0) { + if (!Name.empty()) + DestST->insert(Name, const_cast(RHS)); + } else if (ResolveTypes(Entry, RHS)) { // They look different, save the types 'till later to resolve. DelayedTypesToResolve.push_back(Name); } @@ -219,7 +305,7 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { const std::string &Name = DelayedTypesToResolve[i]; Type *T1 = SrcST->lookup(Name); Type *T2 = DestST->lookup(Name); - if (!ResolveTypes(T2, T1, DestST, Name)) { + if (!ResolveTypes(T2, T1)) { // We are making progress! DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); --i; @@ -232,10 +318,7 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { // two types: { int* } and { opaque* } for (unsigned i = 0, e = DelayedTypesToResolve.size(); i != e; ++i) { const std::string &Name = DelayedTypesToResolve[i]; - PATypeHolder T1(SrcST->lookup(Name)); - PATypeHolder T2(DestST->lookup(Name)); - - if (!RecursiveResolveTypes(T2, T1, DestST, Name)) { + if (!RecursiveResolveTypes(SrcST->lookup(Name), DestST->lookup(Name))) { // We are making progress! DelayedTypesToResolve.erase(DelayedTypesToResolve.begin()+i); @@ -257,6 +340,7 @@ static bool LinkTypes(Module *Dest, const Module *Src, std::string *Err) { return false; } +#ifndef NDEBUG static void PrintMap(const std::map &M) { for (std::map::const_iterator I = M.begin(), E =M.end(); I != E; ++I) { @@ -267,6 +351,7 @@ static void PrintMap(const std::map &M) { cerr << "\n"; } } +#endif // RemapOperand - Use ValueMap to convert constants from one module to another. @@ -305,9 +390,8 @@ static Value *RemapOperand(const Value *In, for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) Ops.push_back(cast(RemapOperand(CE->getOperand(i),ValueMap))); Result = CE->getWithOperands(Ops); - } else if (isa(CPV)) { - assert(0 && "Unmapped global?"); } else { + assert(!isa(CPV) && "Unmapped global?"); assert(0 && "Unknown type of derived type constant value!"); } } else if (isa(In)) { @@ -316,16 +400,17 @@ static Value *RemapOperand(const Value *In, // Cache the mapping in our local map structure if (Result) { - ValueMap.insert(std::make_pair(In, Result)); + ValueMap[In] = Result; return Result; } - +#ifndef NDEBUG cerr << "LinkModules ValueMap: \n"; PrintMap(ValueMap); cerr << "Couldn't remap value: " << (void*)In << " " << *In << "\n"; assert(0 && "Couldn't remap value!"); +#endif return 0; } @@ -351,17 +436,10 @@ static void ForceRenaming(GlobalValue *GV, const std::string &Name) { /// CopyGVAttributes - copy additional attributes (those not needed to construct /// a GlobalValue) from the SrcGV to the DestGV. static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { - // Propagate alignment, visibility and section info. - DestGV->setAlignment(std::max(DestGV->getAlignment(), SrcGV->getAlignment())); - DestGV->setSection(SrcGV->getSection()); - DestGV->setVisibility(SrcGV->getVisibility()); - if (const Function *SrcF = dyn_cast(SrcGV)) { - Function *DestF = cast(DestGV); - DestF->setCallingConv(SrcF->getCallingConv()); - DestF->setParamAttrs(SrcF->getParamAttrs()); - if (SrcF->hasCollector()) - DestF->setCollector(SrcF->getCollector()); - } + // Use the maximum alignment, rather than just copying the alignment of SrcGV. + unsigned Alignment = std::max(DestGV->getAlignment(), SrcGV->getAlignment()); + DestGV->copyAttributesFrom(SrcGV); + DestGV->setAlignment(Alignment); } /// GetLinkageResult - This analyzes the two global values and determines what @@ -371,7 +449,7 @@ static void CopyGVAttributes(GlobalValue *DestGV, const GlobalValue *SrcGV) { /// one), and computes whether this linkage is an error or not. It also performs /// visibility checks: we cannot link together two symbols with different /// visibilities. -static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, +static bool GetLinkageResult(GlobalValue *Dest, const GlobalValue *Src, GlobalValue::LinkageTypes <, bool &LinkFromSrc, std::string *Err) { assert((!Dest || !Src->hasInternalLinkage()) && @@ -381,7 +459,7 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, LinkFromSrc = true; LT = Src->getLinkage(); } else if (Src->isDeclaration()) { - // If Src is external or if both Src & Drc are external.. Just link the + // If Src is external or if both Src & Dest are external.. Just link the // external globals, we aren't adding anything. if (Src->hasDLLImportLinkage()) { // If one of GVs has DLLImport linkage, result should be dllimport'ed. @@ -407,10 +485,11 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, "': can only link appending global with another appending global!"); LinkFromSrc = true; // Special cased. LT = Src->getLinkage(); - } else if (Src->hasWeakLinkage() || Src->hasLinkOnceLinkage()) { - // At this point we know that Dest has LinkOnce, External*, Weak, or - // DLL* linkage. - if ((Dest->hasLinkOnceLinkage() && Src->hasWeakLinkage()) || + } else if (Src->isWeakForLinker()) { + // At this point we know that Dest has LinkOnce, External*, Weak, Common, + // or DLL* linkage. + if ((Dest->hasLinkOnceLinkage() && + (Src->hasWeakLinkage() || Src->hasCommonLinkage())) || Dest->hasExternalWeakLinkage()) { LinkFromSrc = true; LT = Src->getLinkage(); @@ -418,7 +497,7 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, LinkFromSrc = false; LT = Dest->getLinkage(); } - } else if (Dest->hasWeakLinkage() || Dest->hasLinkOnceLinkage()) { + } else if (Dest->isWeakForLinker()) { // At this point we know that Src has External* or DLL* linkage. if (Src->hasExternalWeakLinkage()) { LinkFromSrc = false; @@ -451,23 +530,27 @@ static bool GetLinkageResult(GlobalValue *Dest, GlobalValue *Src, // LinkGlobals - Loop through the global variables in the src module and merge // them into the dest module. -static bool LinkGlobals(Module *Dest, Module *Src, +static bool LinkGlobals(Module *Dest, const Module *Src, std::map &ValueMap, std::multimap &AppendingVars, std::string *Err) { + ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable(); + // Loop over all of the globals in the src module, mapping them over as we go - for (Module::global_iterator I = Src->global_begin(), E = Src->global_end(); - I != E; ++I) { - GlobalVariable *SGV = I; - GlobalVariable *DGV = 0; - // Check to see if may have to link the global. - if (SGV->hasName() && !SGV->hasInternalLinkage()) { - DGV = Dest->getGlobalVariable(SGV->getName()); - if (DGV && DGV->getType() != SGV->getType()) - // If types don't agree due to opaque types, try to resolve them. - RecursiveResolveTypes(SGV->getType(), DGV->getType(), - &Dest->getTypeSymbolTable(), ""); - } + for (Module::const_global_iterator I = Src->global_begin(), + E = Src->global_end(); I != E; ++I) { + const GlobalVariable *SGV = I; + GlobalValue *DGV = 0; + + // Check to see if may have to link the global with the global, alias or + // function. + if (SGV->hasName() && !SGV->hasInternalLinkage()) + DGV = cast_or_null(DestSymTab.lookup(SGV->getNameStart(), + SGV->getNameEnd())); + + // If types don't agree due to opaque types, try to resolve them. + if (DGV && DGV->getType() != SGV->getType()) + RecursiveResolveTypes(SGV->getType(), DGV->getType()); if (DGV && DGV->hasInternalLinkage()) DGV = 0; @@ -484,11 +567,12 @@ static bool LinkGlobals(Module *Dest, Module *Src, if (!DGV) { // No linking to be performed, simply create an identical version of the // symbol over in the dest module... the initializer will be filled in - // later by LinkGlobalInits... + // later by LinkGlobalInits. GlobalVariable *NewDGV = new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(), SGV->getLinkage(), /*init*/0, - SGV->getName(), Dest, SGV->isThreadLocal()); + SGV->getName(), Dest, false, + SGV->getType()->getAddressSpace()); // Propagate alignment, visibility and section info. CopyGVAttributes(NewDGV, SGV); @@ -499,9 +583,10 @@ static bool LinkGlobals(Module *Dest, Module *Src, ForceRenaming(NewDGV, SGV->getName()); // Make sure to remember this mapping... - ValueMap.insert(std::make_pair(SGV, NewDGV)); + ValueMap[SGV] = NewDGV; + + // Keep track that this is an appending variable. if (SGV->hasAppendingLinkage()) - // Keep track that this is an appending variable... AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); } else if (DGV->hasAppendingLinkage()) { // No linking is performed yet. Just insert a new copy of the global, and @@ -511,81 +596,244 @@ static bool LinkGlobals(Module *Dest, Module *Src, GlobalVariable *NewDGV = new GlobalVariable(SGV->getType()->getElementType(), SGV->isConstant(), SGV->getLinkage(), /*init*/0, - "", Dest, SGV->isThreadLocal()); + "", Dest, false, + SGV->getType()->getAddressSpace()); - // Propagate alignment, section and visibility info. + // Set alignment allowing CopyGVAttributes merge it with alignment of SGV. NewDGV->setAlignment(DGV->getAlignment()); + // Propagate alignment, section and visibility info. CopyGVAttributes(NewDGV, SGV); // Make sure to remember this mapping... - ValueMap.insert(std::make_pair(SGV, NewDGV)); + ValueMap[SGV] = NewDGV; // Keep track that this is an appending variable... AppendingVars.insert(std::make_pair(SGV->getName(), NewDGV)); - } else { + } else if (GlobalAlias *DGA = dyn_cast(DGV)) { + // SGV is global, but DGV is alias. The only valid mapping is when SGV is + // external declaration, which is effectively a no-op. Also make sure + // linkage calculation was correct. + if (!SGV->isDeclaration() || LinkFromSrc) + return Error(Err, "Global-Alias Collision on '" + SGV->getName() + + "': symbol multiple defined"); + + // Make sure to remember this mapping. + ValueMap[SGV] = DGA; + } else if (LinkFromSrc) { + // If the types don't match, and if we are to link from the source, nuke + // DGV and create a new one of the appropriate type. Note that the thing + // we are replacing may be a function (if a prototype, weak, etc) or a + // global variable. + GlobalVariable *NewDGV = + new GlobalVariable(SGV->getType()->getElementType(), + SGV->isConstant(), SGV->getLinkage(), + /*init*/0, DGV->getName(), Dest, false, + SGV->getType()->getAddressSpace()); + // Propagate alignment, section, and visibility info. - CopyGVAttributes(DGV, SGV); - - // Otherwise, perform the mapping as instructed by GetLinkageResult. If - // the types don't match, and if we are to link from the source, nuke DGV - // and create a new one of the appropriate type. - if (SGV->getType() != DGV->getType() && LinkFromSrc) { - GlobalVariable *NewDGV = - new GlobalVariable(SGV->getType()->getElementType(), - DGV->isConstant(), DGV->getLinkage()); - NewDGV->setThreadLocal(DGV->isThreadLocal()); - CopyGVAttributes(NewDGV, DGV); - Dest->getGlobalList().insert(DGV, NewDGV); - DGV->replaceAllUsesWith( - ConstantExpr::getBitCast(NewDGV, DGV->getType())); - DGV->eraseFromParent(); - NewDGV->setName(SGV->getName()); - DGV = NewDGV; - } - + CopyGVAttributes(NewDGV, SGV); + DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, DGV->getType())); + + // DGV will conflict with NewDGV because they both had the same + // name. We must erase this now so ForceRenaming doesn't assert + // because DGV might not have internal linkage. + if (GlobalVariable *Var = dyn_cast(DGV)) + Var->eraseFromParent(); + else + cast(DGV)->eraseFromParent(); + DGV = NewDGV; + + // If the symbol table renamed the global, but it is an externally visible + // symbol, DGV must be an existing global with internal linkage. Rename. + if (NewDGV->getValueName() != SGV->getValueName() && + !NewDGV->hasInternalLinkage()) + ForceRenaming(NewDGV, SGV->getName()); + + // Inherit const as appropriate + NewDGV->setConstant(SGV->isConstant()); + + // Set calculated linkage + NewDGV->setLinkage(NewLinkage); + + // Make sure to remember this mapping... + ValueMap[SGV] = ConstantExpr::getBitCast(NewDGV, SGV->getType()); + } else { + // Not "link from source", keep the one in the DestModule and remap the + // input onto it. + + // Special case for const propagation. + if (GlobalVariable *DGVar = dyn_cast(DGV)) + if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant()) + DGVar->setConstant(true); + + // Set calculated linkage DGV->setLinkage(NewLinkage); - - if (LinkFromSrc) { - // Inherit const as appropriate - DGV->setConstant(SGV->isConstant()); - DGV->setInitializer(0); - } else { - if (SGV->isConstant() && !DGV->isConstant()) { - if (DGV->isDeclaration()) - DGV->setConstant(true); - } - SGV->setLinkage(GlobalValue::ExternalLinkage); - SGV->setInitializer(0); - } - - ValueMap.insert( - std::make_pair(SGV, ConstantExpr::getBitCast(DGV, SGV->getType()))); + + // Make sure to remember this mapping... + ValueMap[SGV] = ConstantExpr::getBitCast(DGV, SGV->getType()); } } return false; } +static GlobalValue::LinkageTypes +CalculateAliasLinkage(const GlobalValue *SGV, const GlobalValue *DGV) { + if (SGV->hasExternalLinkage() || DGV->hasExternalLinkage()) + return GlobalValue::ExternalLinkage; + else if (SGV->hasWeakLinkage() || DGV->hasWeakLinkage()) + return GlobalValue::WeakLinkage; + else { + assert(SGV->hasInternalLinkage() && DGV->hasInternalLinkage() && + "Unexpected linkage type"); + return GlobalValue::InternalLinkage; + } +} + // LinkAlias - Loop through the alias in the src module and link them into the -// dest module. -static bool LinkAlias(Module *Dest, const Module *Src, std::string *Err) { +// dest module. We're assuming, that all functions/global variables were already +// linked in. +static bool LinkAlias(Module *Dest, const Module *Src, + std::map &ValueMap, + std::string *Err) { // Loop over all alias in the src module for (Module::const_alias_iterator I = Src->alias_begin(), E = Src->alias_end(); I != E; ++I) { - const GlobalAlias *GA = I; - - GlobalValue *NewAliased = NULL; - const GlobalValue *Aliased = GA->getAliasedGlobal(); - if (isa(*Aliased)) - NewAliased = Dest->getGlobalVariable(Aliased->getName()); - else if (isa(*Aliased)) - NewAliased = Dest->getFunction(Aliased->getName()); - // FIXME: we should handle the bitcast alias. - assert(NewAliased && "Can't find the aliased GV."); - - GlobalAlias *NewGA = new GlobalAlias(GA->getType(), GA->getLinkage(), - GA->getName(), NewAliased, Dest); - CopyGVAttributes(NewGA, GA); + const GlobalAlias *SGA = I; + const GlobalValue *SAliasee = SGA->getAliasedGlobal(); + GlobalAlias *NewGA = NULL; + + // Globals were already linked, thus we can just query ValueMap for variant + // of SAliasee in Dest. + std::map::const_iterator VMI = ValueMap.find(SAliasee); + assert(VMI != ValueMap.end() && "Aliasee not linked"); + GlobalValue* DAliasee = cast(VMI->second); + GlobalValue* DGV = NULL; + + // Try to find something 'similar' to SGA in destination module. + if (!DGV && !SGA->hasInternalLinkage()) { + DGV = Dest->getNamedAlias(SGA->getName()); + + // If types don't agree due to opaque types, try to resolve them. + if (DGV && DGV->getType() != SGA->getType()) + RecursiveResolveTypes(SGA->getType(), DGV->getType()); + } + + if (!DGV && !SGA->hasInternalLinkage()) { + DGV = Dest->getGlobalVariable(SGA->getName()); + + // If types don't agree due to opaque types, try to resolve them. + if (DGV && DGV->getType() != SGA->getType()) + RecursiveResolveTypes(SGA->getType(), DGV->getType()); + } + + if (!DGV && !SGA->hasInternalLinkage()) { + DGV = Dest->getFunction(SGA->getName()); + + // If types don't agree due to opaque types, try to resolve them. + if (DGV && DGV->getType() != SGA->getType()) + RecursiveResolveTypes(SGA->getType(), DGV->getType()); + } + + // No linking to be performed on internal stuff. + if (DGV && DGV->hasInternalLinkage()) + DGV = NULL; + + if (GlobalAlias *DGA = dyn_cast_or_null(DGV)) { + // Types are known to be the same, check whether aliasees equal. As + // globals are already linked we just need query ValueMap to find the + // mapping. + if (DAliasee == DGA->getAliasedGlobal()) { + // This is just two copies of the same alias. Propagate linkage, if + // necessary. + DGA->setLinkage(CalculateAliasLinkage(SGA, DGA)); + + NewGA = DGA; + // Proceed to 'common' steps + } else + return Error(Err, "Alias Collision on '" + SGA->getName()+ + "': aliases have different aliasees"); + } else if (GlobalVariable *DGVar = dyn_cast_or_null(DGV)) { + // The only allowed way is to link alias with external declaration or weak + // symbol.. + if (DGVar->isDeclaration() || DGVar->isWeakForLinker()) { + // But only if aliasee is global too... + if (!isa(DAliasee)) + return Error(Err, "Global-Alias Collision on '" + SGA->getName() + + "': aliasee is not global variable"); + + NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), + SGA->getName(), DAliasee, Dest); + CopyGVAttributes(NewGA, SGA); + + // Any uses of DGV need to change to NewGA, with cast, if needed. + if (SGA->getType() != DGVar->getType()) + DGVar->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA, + DGVar->getType())); + else + DGVar->replaceAllUsesWith(NewGA); + + // DGVar will conflict with NewGA because they both had the same + // name. We must erase this now so ForceRenaming doesn't assert + // because DGV might not have internal linkage. + DGVar->eraseFromParent(); + + // Proceed to 'common' steps + } else + return Error(Err, "Global-Alias Collision on '" + SGA->getName() + + "': symbol multiple defined"); + } else if (Function *DF = dyn_cast_or_null(DGV)) { + // The only allowed way is to link alias with external declaration or weak + // symbol... + if (DF->isDeclaration() || DF->isWeakForLinker()) { + // But only if aliasee is function too... + if (!isa(DAliasee)) + return Error(Err, "Function-Alias Collision on '" + SGA->getName() + + "': aliasee is not function"); + + NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), + SGA->getName(), DAliasee, Dest); + CopyGVAttributes(NewGA, SGA); + + // Any uses of DF need to change to NewGA, with cast, if needed. + if (SGA->getType() != DF->getType()) + DF->replaceAllUsesWith(ConstantExpr::getBitCast(NewGA, + DF->getType())); + else + DF->replaceAllUsesWith(NewGA); + + // DF will conflict with NewGA because they both had the same + // name. We must erase this now so ForceRenaming doesn't assert + // because DF might not have internal linkage. + DF->eraseFromParent(); + + // Proceed to 'common' steps + } else + return Error(Err, "Function-Alias Collision on '" + SGA->getName() + + "': symbol multiple defined"); + } else { + // No linking to be performed, simply create an identical version of the + // alias over in the dest module... + + NewGA = new GlobalAlias(SGA->getType(), SGA->getLinkage(), + SGA->getName(), DAliasee, Dest); + CopyGVAttributes(NewGA, SGA); + + // Proceed to 'common' steps + } + + assert(NewGA && "No alias was created in destination module!"); + + // If the symbol table renamed the alias, but it is an externally visible + // symbol, DGA must be an global value with internal linkage. Rename it. + if (NewGA->getName() != SGA->getName() && + !NewGA->hasInternalLinkage()) + ForceRenaming(NewGA, SGA->getName()); + + // Remember this mapping so uses in the source module get remapped + // later by RemapOperand. + ValueMap[SGA] = NewGA; } + return false; } @@ -595,7 +843,6 @@ static bool LinkAlias(Module *Dest, const Module *Src, std::string *Err) { static bool LinkGlobalInits(Module *Dest, const Module *Src, std::map &ValueMap, std::string *Err) { - // Loop over all of the globals in the src module, mapping them over as we go for (Module::const_global_iterator I = Src->global_begin(), E = Src->global_end(); I != E; ++I) { @@ -606,17 +853,17 @@ static bool LinkGlobalInits(Module *Dest, const Module *Src, Constant *SInit = cast(RemapOperand(SGV->getInitializer(), ValueMap)); - GlobalVariable *DGV = cast(ValueMap[SGV]); + GlobalVariable *DGV = + cast(ValueMap[SGV]->stripPointerCasts()); if (DGV->hasInitializer()) { if (SGV->hasExternalLinkage()) { if (DGV->getInitializer() != SInit) - return Error(Err, "Global Variable Collision on '" + - ToStr(SGV->getType(), Src) +"':%"+SGV->getName()+ - " - Global variables have different initializers"); - } else if (DGV->hasLinkOnceLinkage() || DGV->hasWeakLinkage()) { + return Error(Err, "Global Variable Collision on '" + SGV->getName() + + "': global variables have different initializers"); + } else if (DGV->isWeakForLinker()) { // Nothing is required, mapped values will take the new global // automatically. - } else if (SGV->hasLinkOnceLinkage() || SGV->hasWeakLinkage()) { + } else if (SGV->isWeakForLinker()) { // Nothing is required, mapped values will take the new global // automatically. } else if (DGV->hasAppendingLinkage()) { @@ -640,39 +887,86 @@ static bool LinkGlobalInits(Module *Dest, const Module *Src, static bool LinkFunctionProtos(Module *Dest, const Module *Src, std::map &ValueMap, std::string *Err) { + ValueSymbolTable &DestSymTab = Dest->getValueSymbolTable(); + // Loop over all of the functions in the src module, mapping them over for (Module::const_iterator I = Src->begin(), E = Src->end(); I != E; ++I) { const Function *SF = I; // SrcFunction - Function *DF = 0; - if (SF->hasName() && !SF->hasInternalLinkage()) { - // Check to see if may have to link the function. - DF = Dest->getFunction(SF->getName()); - if (DF && SF->getType() != DF->getType()) - // If types don't agree because of opaque, try to resolve them - RecursiveResolveTypes(SF->getType(), DF->getType(), - &Dest->getTypeSymbolTable(), ""); + GlobalValue *DGV = 0; + Value *MappedDF; + + // Check to see if may have to link the function with the global, alias or + // function. + if (SF->hasName() && !SF->hasInternalLinkage()) + DGV = cast_or_null(DestSymTab.lookup(SF->getNameStart(), + SF->getNameEnd())); + + // If types don't agree due to opaque types, try to resolve them. + if (DGV && DGV->getType() != SF->getType()) + RecursiveResolveTypes(SF->getType(), DGV->getType()); + + if (DGV && DGV->hasInternalLinkage()) + DGV = 0; + + // If there is no linkage to be performed, just bring over SF without + // modifying it. + if (DGV == 0) { + // Function does not already exist, simply insert an function signature + // identical to SF into the dest module. + Function *NewDF = Function::Create(SF->getFunctionType(), + SF->getLinkage(), + SF->getName(), Dest); + CopyGVAttributes(NewDF, SF); + + // If the LLVM runtime renamed the function, but it is an externally + // visible symbol, DF must be an existing function with internal linkage. + // Rename it. + if (!NewDF->hasInternalLinkage() && NewDF->getName() != SF->getName()) + ForceRenaming(NewDF, SF->getName()); + + // ... and remember this mapping... + ValueMap[SF] = NewDF; + continue; + } else if (GlobalAlias *DGA = dyn_cast(DGV)) { + // SF is function, but DF is alias. + // The only valid mappings are: + // - SF is external declaration, which is effectively a no-op. + // - SF is weak, when we just need to throw SF out. + if (!SF->isDeclaration() && !SF->isWeakForLinker()) + return Error(Err, "Function-Alias Collision on '" + SF->getName() + + "': symbol multiple defined"); + + // Make sure to remember this mapping... + ValueMap[SF] = ConstantExpr::getBitCast(DGA, SF->getType()); + continue; } - // Check visibility - if (DF && !DF->hasInternalLinkage() && - SF->getVisibility() != DF->getVisibility()) { + Function* DF = cast(DGV); + // If types don't agree because of opaque, try to resolve them. + if (SF->getType() != DF->getType()) + RecursiveResolveTypes(SF->getType(), DF->getType()); + + // Check visibility, merging if a definition overrides a prototype. + if (SF->getVisibility() != DF->getVisibility()) { // If one is a prototype, ignore its visibility. Prototypes are always // overridden by the definition. if (!SF->isDeclaration() && !DF->isDeclaration()) return Error(Err, "Linking functions named '" + SF->getName() + "': symbols have different visibilities!"); + + // Otherwise, replace the visibility of DF if DF is a prototype. + if (DF->isDeclaration()) + DF->setVisibility(SF->getVisibility()); } - if (DF && DF->hasInternalLinkage()) - DF = NULL; - - if (DF && DF->getType() != SF->getType()) { + if (DF->getType() != SF->getType()) { if (DF->isDeclaration() && !SF->isDeclaration()) { // We have a definition of the same name but different type in the // source module. Copy the prototype to the destination and replace // uses of the destination's prototype with the new prototype. - Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(), - SF->getName(), Dest); + Function *NewDF = Function::Create(SF->getFunctionType(), + SF->getLinkage(), + SF->getName(), Dest); CopyGVAttributes(NewDF, SF); // Any uses of DF need to change to NewDF, with cast @@ -692,77 +986,75 @@ static bool LinkFunctionProtos(Module *Dest, const Module *Src, // Remember this mapping so uses in the source module get remapped // later by RemapOperand. ValueMap[SF] = NewDF; - } else if (SF->isDeclaration()) { - // We have two functions of the same name but different type and the - // source is a declaration while the destination is not. Any use of - // the source must be mapped to the destination, with a cast. - ValueMap[SF] = ConstantExpr::getBitCast(DF, SF->getType()); + continue; } else { - // We have two functions of the same name but different types and they - // are both definitions. This is an error. - return Error(Err, "Function '" + DF->getName() + "' defined as both '" + - ToStr(SF->getFunctionType(), Src) + "' and '" + - ToStr(DF->getFunctionType(), Dest) + "'"); + // We have two functions of the same name but different type. Any use + // of the source must be mapped to the destination, with a cast. + MappedDF = ConstantExpr::getBitCast(DF, SF->getType()); } - } else if (!DF || SF->hasInternalLinkage() || DF->hasInternalLinkage()) { - // Function does not already exist, simply insert an function signature - // identical to SF into the dest module. - Function *NewDF = new Function(SF->getFunctionType(), SF->getLinkage(), - SF->getName(), Dest); - CopyGVAttributes(NewDF, SF); - - // If the LLVM runtime renamed the function, but it is an externally - // visible symbol, DF must be an existing function with internal linkage. - // Rename it. - if (NewDF->getName() != SF->getName() && !NewDF->hasInternalLinkage()) - ForceRenaming(NewDF, SF->getName()); - - // ... and remember this mapping... - ValueMap.insert(std::make_pair(SF, NewDF)); - } else if (SF->isDeclaration()) { + } else { + MappedDF = DF; + } + + if (SF->isDeclaration()) { // If SF is a declaration or if both SF & DF are declarations, just link // the declarations, we aren't adding anything. if (SF->hasDLLImportLinkage()) { if (DF->isDeclaration()) { - ValueMap.insert(std::make_pair(SF, DF)); + ValueMap[SF] = MappedDF; DF->setLinkage(SF->getLinkage()); - } + } } else { - ValueMap.insert(std::make_pair(SF, DF)); - } - } else if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) { - // If DF is external but SF is not... - // Link the external functions, update linkage qualifiers - ValueMap.insert(std::make_pair(SF, DF)); + ValueMap[SF] = MappedDF; + } + continue; + } + + // If DF is external but SF is not, link the external functions, update + // linkage qualifiers. + if (DF->isDeclaration() && !DF->hasDLLImportLinkage()) { + ValueMap.insert(std::make_pair(SF, MappedDF)); DF->setLinkage(SF->getLinkage()); - // Visibility of prototype is overridden by vis of definition. - DF->setVisibility(SF->getVisibility()); - } else if (SF->hasWeakLinkage() || SF->hasLinkOnceLinkage()) { - // At this point we know that DF has LinkOnce, Weak, or External* linkage. - ValueMap.insert(std::make_pair(SF, DF)); + continue; + } + + // At this point we know that DF has LinkOnce, Weak, or External* linkage. + if (SF->isWeakForLinker()) { + ValueMap[SF] = MappedDF; // Linkonce+Weak = Weak // *+External Weak = * - if ((DF->hasLinkOnceLinkage() && SF->hasWeakLinkage()) || + if ((DF->hasLinkOnceLinkage() && + (SF->hasWeakLinkage() || SF->hasCommonLinkage())) || DF->hasExternalWeakLinkage()) DF->setLinkage(SF->getLinkage()); - } else if (DF->hasWeakLinkage() || DF->hasLinkOnceLinkage()) { + continue; + } + + if (DF->isWeakForLinker()) { // At this point we know that SF has LinkOnce or External* linkage. - ValueMap.insert(std::make_pair(SF, DF)); - if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage()) - // Don't inherit linkonce & external weak linkage + ValueMap[SF] = MappedDF; + + // If the source function has stronger linkage than the destination, + // its body and linkage should override ours. + if (!SF->hasLinkOnceLinkage() && !SF->hasExternalWeakLinkage()) { + // Don't inherit linkonce & external weak linkage. DF->setLinkage(SF->getLinkage()); - } else if (SF->getLinkage() != DF->getLinkage()) { - return Error(Err, "Functions named '" + SF->getName() + - "' have different linkage specifiers!"); - } else if (SF->hasExternalLinkage()) { - // The function is defined identically in both modules!! + DF->deleteBody(); + } + continue; + } + + if (SF->getLinkage() != DF->getLinkage()) + return Error(Err, "Functions named '" + SF->getName() + + "' have different linkage specifiers!"); + + // The function is defined identically in both modules! + if (SF->hasExternalLinkage()) return Error(Err, "Function '" + ToStr(SF->getFunctionType(), Src) + "':\"" + SF->getName() + "\" - Function is already defined!"); - } else { - assert(0 && "Unknown linkage configuration found!"); - } + assert(0 && "Unknown linkage configuration found!"); } return false; } @@ -782,7 +1074,7 @@ static bool LinkFunctionBody(Function *Dest, Function *Src, DI->setName(I->getName()); // Copy the name information over... // Add a mapping to our local map - ValueMap.insert(std::make_pair(I, DI)); + ValueMap[I] = DI; } // Splice the body of the source function into the dest function. @@ -820,10 +1112,10 @@ static bool LinkFunctionBodies(Module *Dest, Module *Src, // go for (Module::iterator SF = Src->begin(), E = Src->end(); SF != E; ++SF) { if (!SF->isDeclaration()) { // No body if function is external - Function *DF = cast(ValueMap[SF]); // Destination function + Function *DF = dyn_cast(ValueMap[SF]); // Destination function // DF not external SF external? - if (DF->isDeclaration()) + if (DF && DF->isDeclaration()) // Only provide the function body if there isn't one already. if (LinkFunctionBody(DF, SF, ValueMap, Err)) return true; @@ -884,7 +1176,8 @@ static bool LinkAppendingVars(Module *M, // Create the new global variable... GlobalVariable *NG = new GlobalVariable(NewType, G1->isConstant(), G1->getLinkage(), - /*init*/0, First->first, M, G1->isThreadLocal()); + /*init*/0, First->first, M, G1->isThreadLocal(), + G1->getType()->getAddressSpace()); // Propagate alignment, visibility and section info. CopyGVAttributes(NG, G1); @@ -934,6 +1227,15 @@ static bool LinkAppendingVars(Module *M, return false; } +static bool ResolveAliases(Module *Dest) { + for (Module::alias_iterator I = Dest->alias_begin(), E = Dest->alias_end(); + I != E; ++I) + if (const GlobalValue *GV = I->resolveAliasedGlobal()) + if (!GV->isDeclaration()) + I->replaceAllUsesWith(const_cast(GV)); + + return false; +} // LinkModules - This function links two modules together, with the resulting // left module modified to be the composite of the two input modules. If an @@ -951,21 +1253,24 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { } else { std::string DataLayout; - if (Dest->getEndianness() == Module::AnyEndianness) + if (Dest->getEndianness() == Module::AnyEndianness) { if (Src->getEndianness() == Module::BigEndian) DataLayout.append("E"); else if (Src->getEndianness() == Module::LittleEndian) DataLayout.append("e"); - if (Dest->getPointerSize() == Module::AnyPointerSize) + } + + if (Dest->getPointerSize() == Module::AnyPointerSize) { if (Src->getPointerSize() == Module::Pointer64) DataLayout.append(DataLayout.length() == 0 ? "p:64:64" : "-p:64:64"); else if (Src->getPointerSize() == Module::Pointer32) DataLayout.append(DataLayout.length() == 0 ? "p:32:32" : "-p:32:32"); + } Dest->setDataLayout(DataLayout); } } - // COpy the target triple from the source to dest if the dest's is empty + // Copy the target triple from the source to dest if the dest's is empty. if (Dest->getTargetTriple().empty() && !Src->getTargetTriple().empty()) Dest->setTargetTriple(Src->getTargetTriple()); @@ -976,7 +1281,7 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { Dest->getTargetTriple() != Src->getTargetTriple()) cerr << "WARNING: Linking two modules of different target triples!\n"; - // Append the module inline asm string + // Append the module inline asm string. if (!Src->getModuleInlineAsm().empty()) { if (Dest->getModuleInlineAsm().empty()) Dest->setModuleInlineAsm(Src->getModuleInlineAsm()); @@ -988,12 +1293,9 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { // Update the destination module's dependent libraries list with the libraries // from the source module. There's no opportunity for duplicates here as the // Module ensures that duplicate insertions are discarded. - Module::lib_iterator SI = Src->lib_begin(); - Module::lib_iterator SE = Src->lib_end(); - while ( SI != SE ) { + for (Module::lib_iterator SI = Src->lib_begin(), SE = Src->lib_end(); + SI != SE; ++SI) Dest->addLibrary(*SI); - ++SI; - } // LinkTypes - Go through the symbol table of the Src module and see if any // types are named in the src module that are not named in the Dst module. @@ -1030,6 +1332,11 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { if (LinkFunctionProtos(Dest, Src, ValueMap, ErrorMsg)) return true; + // If there were any alias, link them now. We really need to do this now, + // because all of the aliases that may be referenced need to be available in + // ValueMap + if (LinkAlias(Dest, Src, ValueMap, ErrorMsg)) return true; + // Update the initializers in the Dest module now that all globals that may // be referenced are in Dest. if (LinkGlobalInits(Dest, Src, ValueMap, ErrorMsg)) return true; @@ -1042,8 +1349,8 @@ Linker::LinkModules(Module *Dest, Module *Src, std::string *ErrorMsg) { // If there were any appending global variables, link them together now. if (LinkAppendingVars(Dest, AppendingVars, ErrorMsg)) return true; - // If there were any alias, link them now. - if (LinkAlias(Dest, Src, ErrorMsg)) return true; + // Resolve all uses of aliases with aliasees + if (ResolveAliases(Dest)) return true; // If the source library's module id is in the dependent library list of the // destination library, remove it since that module is now linked in.